+---------------+          +-----------------+          +-----------------+
|  version      |<-----+   | building_type   |<-----+   | building        |
+---------------+      |   +-----------------+      |   +-----------------+
| - id (PK)     |      |   | - id (PK)       |      |   | - id (PK)       |
| - name        |      +---|- version        |      +---|- type           |
| - description |          | - name          |          | - name          |
+---------------+          +-----------------+          | - power         |
                              |                         | - icon_url      |
                              |                         | - description   |
                              |                         +-----------------+
                              |
                              |                         +-----------------+
                              +-----------------------| building_cost   |
                                                      +-----------------+
                                                      | - id (PK)       |
                                                      | - building_id   |
                                                      | - item_id       |
                                                      | - amount        |
                                                      +-----------------+

+---------------+          +-----------------+          +-----------------+
|  item_type    |<-----+   | item            |<-----+   | recipe          |
+---------------+      |   +-----------------+      |   +-----------------+
| - id (PK)     |      +---|- type           |      +---|- id (PK)        |
| - name        |          | - id (PK)       |          | - name          |
| - version_id  |          | - name          |          | - time          |
| - state       |          | - default_recipe|          | - power         |
+---------------+          | - version       |          | - version       |
                           | - icon_url      |          +-----------------+
                            | - stack_size    |               |
                            +-----------------+               |
                                      |                       |
                                      |                       |
+-----------------+          +-----------------+    +-----------------+
| recipe_ingredient|         | recipe_product  |    | recipe_building |
+-----------------+          +-----------------+    +-----------------+
| - id (PK)       |          | - id (PK)       |    | - id (PK)       |
| - recipe_id     |          | - recipe_id     |    | - building_id   |
| - item_id       |          | - item_id       |    | - recipe_id     |
| - amount        |          | - amount        |    +-----------------+
+-----------------+          +-----------------+    